From 880fa0a8daf3e766dc4422f9db2a71caa1ffe3a0 Mon Sep 17 00:00:00 2001 From: Tim Newsome Date: Tue, 25 Apr 2023 10:32:12 -0700 Subject: [PATCH] target/riscv: Support VS-stage and G-stage address translation. These are used in hypervisor mode. Change-Id: I5f773816f73c83b4ae57727fbc3b36b65b6185eb Signed-off-by: Tim Newsome --- src/target/riscv/riscv.c | 217 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 212 insertions(+), 5 deletions(-) diff --git a/src/target/riscv/riscv.c b/src/target/riscv/riscv.c index dddef1f6c..0df3df37f 100644 --- a/src/target/riscv/riscv.c +++ b/src/target/riscv/riscv.c @@ -159,6 +159,19 @@ static const virt2phys_info_t sv32 = { .pa_ppn_mask = {0x3ff, 0xfff}, }; +static const virt2phys_info_t sv32x4 = { + .name = "Sv32x4", + .va_bits = 34, + .level = 2, + .pte_shift = 2, + .vpn_shift = {12, 22}, + .vpn_mask = {0x3ff, 0xfff}, + .pte_ppn_shift = {10, 20}, + .pte_ppn_mask = {0x3ff, 0xfff}, + .pa_ppn_shift = {12, 22}, + .pa_ppn_mask = {0x3ff, 0xfff}, +}; + static const virt2phys_info_t sv39 = { .name = "Sv39", .va_bits = 39, @@ -172,6 +185,19 @@ static const virt2phys_info_t sv39 = { .pa_ppn_mask = {0x1ff, 0x1ff, 0x3ffffff}, }; +static const virt2phys_info_t sv39x4 = { + .name = "Sv39x4", + .va_bits = 41, + .level = 3, + .pte_shift = 3, + .vpn_shift = {12, 21, 30}, + .vpn_mask = {0x1ff, 0x1ff, 0x7ff}, + .pte_ppn_shift = {10, 19, 28}, + .pte_ppn_mask = {0x1ff, 0x1ff, 0x3ffffff}, + .pa_ppn_shift = {12, 21, 30}, + .pa_ppn_mask = {0x1ff, 0x1ff, 0x3ffffff}, +}; + static const virt2phys_info_t sv48 = { .name = "Sv48", .va_bits = 48, @@ -185,6 +211,19 @@ static const virt2phys_info_t sv48 = { .pa_ppn_mask = {0x1ff, 0x1ff, 0x1ff, 0x1ffff}, }; +static const virt2phys_info_t sv48x4 = { + .name = "Sv48x4", + .va_bits = 50, + .level = 4, + .pte_shift = 3, + .vpn_shift = {12, 21, 30, 39}, + .vpn_mask = {0x1ff, 0x1ff, 0x1ff, 0x7ff}, + .pte_ppn_shift = {10, 19, 28, 37}, + .pte_ppn_mask = {0x1ff, 0x1ff, 0x1ff, 0x1ffff}, + .pa_ppn_shift = {12, 21, 30, 39}, + .pa_ppn_mask = {0x1ff, 0x1ff, 0x1ff, 0x7ffff}, +}; + static enum riscv_halt_reason riscv_halt_reason(struct target *target); static void riscv_info_init(struct target *target, struct riscv_info *r); static void riscv_invalidate_register_cache(struct target *target); @@ -1891,8 +1930,6 @@ static int riscv_effective_privilege_mode(struct target *target, int *v_mode, in static int riscv_mmu(struct target *target, int *enabled) { - unsigned int xlen = riscv_xlen(target); - if (!riscv_enable_virt2phys) { *enabled = 0; return ERROR_OK; @@ -1910,6 +1947,55 @@ static int riscv_mmu(struct target *target, int *enabled) if (riscv_effective_privilege_mode(target, &v_mode, &effective_mode) != ERROR_OK) return ERROR_FAIL; + unsigned int xlen = riscv_xlen(target); + + if (v_mode) { + /* vsatp and hgatp registers are considered active for the + * purposes of the address-translation algorithm unless the + * effective privilege mode is U and hstatus.HU=0. */ + if (effective_mode == PRV_U) { + riscv_reg_t hstatus; + if (riscv_get_register(target, &hstatus, GDB_REGNO_HSTATUS) != ERROR_OK) { + LOG_ERROR("Failed to read hstatus register."); + return ERROR_FAIL; + } + + if (get_field(hstatus, HSTATUS_HU) == 0) + /* In hypervisor mode regular satp translation + * doesn't happen. */ + return ERROR_OK; + } + + riscv_reg_t vsatp; + if (riscv_get_register(target, &vsatp, GDB_REGNO_VSATP) != ERROR_OK) { + LOG_TARGET_ERROR(target, "Failed to read vsatp register; priv=0x%" PRIx64, + priv); + return ERROR_FAIL; + } + /* vsatp is identical to satp, so we can use the satp macros. */ + if (RISCV_SATP_MODE(xlen) != SATP_MODE_OFF) { + LOG_TARGET_DEBUG(target, "VS-stage translation is enabled."); + *enabled = 1; + return ERROR_OK; + } + + riscv_reg_t hgatp; + if (riscv_get_register(target, &hgatp, GDB_REGNO_HGATP) != ERROR_OK) { + LOG_TARGET_ERROR(target, "Failed to read hgatp register; priv=0x%" PRIx64, + priv); + return ERROR_FAIL; + } + if (RISCV_HGATP_MODE(xlen) != HGATP_MODE_OFF) { + LOG_TARGET_DEBUG(target, "G-stage address translation is enabled."); + *enabled = 1; + } else { + LOG_TARGET_DEBUG(target, "No V-mode address translation enabled."); + *enabled = 0; + } + + return ERROR_OK; + } + /* Don't use MMU in explicit or effective M (machine) mode */ if (effective_mode == PRV_M) { LOG_TARGET_DEBUG(target, "SATP/MMU ignored in Machine mode."); @@ -1936,9 +2022,12 @@ static int riscv_mmu(struct target *target, int *enabled) return ERROR_OK; } -/* Translate address from virtual to physical, using info and ppn. */ +/* Translate address from virtual to physical, using info and ppn. + * If extra_info is non-NULL, then translate page table accesses for the primary + * translation using extra_info and extra_ppn. */ static int riscv_address_translate(struct target *target, const virt2phys_info_t *info, target_addr_t ppn, + const virt2phys_info_t *extra_info, target_addr_t extra_ppn, target_addr_t virtual, target_addr_t *physical) { RISCV_INFO(r); @@ -1964,6 +2053,14 @@ static int riscv_address_translate(struct target *target, uint64_t vpn = virtual >> info->vpn_shift[i]; vpn &= info->vpn_mask[i]; target_addr_t pte_address = table_address + (vpn << info->pte_shift); + + if (extra_info) { + /* Perform extra stage translation. */ + if (riscv_address_translate(target, extra_info, extra_ppn, + NULL, 0, pte_address, &pte_address) != ERROR_OK) + return ERROR_FAIL; + } + uint8_t buffer[8]; assert(info->pte_shift <= 3); int retval = r->read_memory(target, pte_address, @@ -2016,22 +2113,131 @@ static int riscv_address_translate(struct target *target, return ERROR_OK; } +/* Virtual to physical translation for hypervisor mode. */ +static int riscv_virt2phys_v(struct target *target, target_addr_t virtual, target_addr_t *physical) +{ + riscv_reg_t vsatp; + if (riscv_get_register(target, &vsatp, GDB_REGNO_VSATP) != ERROR_OK) { + LOG_TARGET_ERROR(target, "Failed to read vsatp register."); + return ERROR_FAIL; + } + /* vsatp is identical to satp, so we can use the satp macros. */ + unsigned int xlen = riscv_xlen(target); + int vsatp_mode = get_field(vsatp, RISCV_SATP_MODE(xlen)); + LOG_TARGET_DEBUG(target, "VS-stage translation mode: %d", vsatp_mode); + riscv_reg_t hgatp; + if (riscv_get_register(target, &hgatp, GDB_REGNO_HGATP) != ERROR_OK) { + LOG_TARGET_ERROR(target, "Failed to read hgatp register."); + return ERROR_FAIL; + } + int hgatp_mode = get_field(vsatp, RISCV_HGATP_MODE(xlen)); + LOG_TARGET_DEBUG(target, "G-stage translation mode: %d", hgatp_mode); + + const virt2phys_info_t *vsatp_info; + /* VS-stage address translation. */ + switch (vsatp_mode) { + case SATP_MODE_SV32: + vsatp_info = &sv32; + break; + case SATP_MODE_SV39: + vsatp_info = &sv39; + break; + case SATP_MODE_SV48: + vsatp_info = &sv48; + break; + case SATP_MODE_OFF: + vsatp_info = NULL; + break; + default: + LOG_TARGET_ERROR(target, + "vsatp mode %d is not supported. (vsatp: 0x%" PRIx64 ")", + vsatp_mode, vsatp); + return ERROR_FAIL; + } + + const virt2phys_info_t *hgatp_info; + /* G-stage address translation. */ + switch (hgatp_mode) { + case HGATP_MODE_SV32X4: + hgatp_info = &sv32x4; + break; + case HGATP_MODE_SV39X4: + hgatp_info = &sv39x4; + break; + case HGATP_MODE_SV48X4: + hgatp_info = &sv48x4; + break; + case HGATP_MODE_OFF: + hgatp_info = NULL; + break; + default: + LOG_TARGET_ERROR(target, + "hgatp mode %d is not supported. (hgatp: 0x%" PRIx64 ")", + hgatp_mode, hgatp); + return ERROR_FAIL; + } + + /* For any virtual memory access, the original virtual address is + * converted in the first stage by VS-level address translation, + * as controlled by the vsatp register, into a guest physical + * address. */ + target_addr_t guest_physical; + if (vsatp_info) { + /* When V=1, memory accesses that would normally bypass + * address translation are subject to G- stage address + * translation alone. This includes memory accesses made + * in support of VS-stage address translation, such as + * reads and writes of VS-level page tables. */ + + if (riscv_address_translate(target, + vsatp_info, get_field(vsatp, RISCV_SATP_PPN(xlen)), + hgatp_info, get_field(hgatp, RISCV_SATP_PPN(xlen)), + virtual, &guest_physical) != ERROR_OK) + return ERROR_FAIL; + } else { + guest_physical = virtual; + } + + /* The guest physical address is then converted in the second + * stage by guest physical address translation, as controlled by + * the hgatp register, into a supervisor physical address. */ + if (hgatp_info) { + if (riscv_address_translate(target, + hgatp_info, get_field(hgatp, RISCV_HGATP_PPN(xlen)), + NULL, 0, + guest_physical, physical) != ERROR_OK) + return ERROR_FAIL; + } else { + *physical = guest_physical; + } + + return ERROR_OK; +} + static int riscv_virt2phys(struct target *target, target_addr_t virtual, target_addr_t *physical) { int enabled; - if (riscv_mmu(target, &enabled) != ERROR_OK) return ERROR_FAIL; if (!enabled) return ERROR_FAIL; - unsigned xlen = riscv_xlen(target); + + riscv_reg_t priv; + if (riscv_get_register(target, &priv, GDB_REGNO_PRIV) != ERROR_OK) { + LOG_ERROR("Failed to read priv register."); + return ERROR_FAIL; + } + + if (priv & VIRT_PRIV_V) + return riscv_virt2phys_v(target, virtual, physical); riscv_reg_t satp_value; int result = riscv_get_register(target, &satp_value, GDB_REGNO_SATP); if (result != ERROR_OK) return result; + unsigned int xlen = riscv_xlen(target); int satp_mode = get_field(satp_value, RISCV_SATP_MODE(xlen)); const virt2phys_info_t *satp_info; switch (satp_mode) { @@ -2056,6 +2262,7 @@ static int riscv_virt2phys(struct target *target, target_addr_t virtual, target_ return riscv_address_translate(target, satp_info, get_field(satp_value, RISCV_SATP_PPN(xlen)), + NULL, 0, virtual, physical); }